PIC16F84-04I/SO - 4MHz 8-bit Flash MCU 1.75KB | Microchip
MPN: PIC16F84-04I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.4 | $3.40 |
| 10 | $3.1 | $31.00 |
| 100 | $2.78 | $278.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
PIC16F84-04I/SO Overview
A PIC microcontroller (Peripheral Interface Controller) is a Harvard-architecture 8-bit RISC MCU family originally developed by General Instrument and commercialized by Microchip. It belongs to the larger embedded microcontroller hierarchy: MCU -> microcontroller -> embedded processor -> semiconductor IC. PIC MCUs combine a small instruction set (35 single-word instructions in the mid-range family), integrated Flash program memory, on-chip EEPROM/data RAM, and dedicated peripherals, making them ideal for cost-sensitive and low-power embedded applications.
The PIC16F84-04I/SO is built around a 14-bit instruction word, 8-bit data path, with four interrupt sources and a hardware stack depth of 8. Key on-chip features include a watchdog timer (WDT), power-on reset (POR), brown-out reset (BOR), a 10-bit capture/compare/PWM (CCP) module on the initial clock variant, and an internal RC oscillator option. The device supports in-circuit serial programming (ICSP) for production-line Flash updates without removing the part.
Typical applications include hobby and educational projects, automotive body electronics, industrial control panels, low-end remote controls, appliance controllers, and legacy product maintenance designs. The 4 MHz oscillator and 4 MHz internal operation make it well suited to deterministic control loops where precise timing and short interrupt latency are required.
When designing with the PIC16F84, ensure the supply rail is decoupled close to VDD with a 100 nF ceramic capacitor, and connect the MCLR pin through a pull-up for proper reset behavior. Note that newer designs typically migrate to the PIC16F84A or PIC16F628A for extended memory and additional peripherals, but PIC16F84-04I/SO remains a supported part with stable firmware compatibility.
This page synthesizes current distributor pricing, parametric drop-in alternatives including PIC16F84A-04I/SO, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16F84-04I/SO — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16F84-04I/SO (same form factor and footprint) — differing in Core Architecture, Package, Timers, Operating Temperature, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F84A-04I/SO
✅ Drop-In✓ In Stock
$3.59 / Unit
View Datasheet →PIC16F84A-04I/P
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC16F84-04I/P
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16F84-04/SO
✅ Drop-In✓ In Stock
$3.19 / Unit
View Datasheet →PIC16F628A-04I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F88-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F84-04I/SO Maximum Ratings & Electrical Characteristics
| Family | PIC16F84 (PIC 16F, mid-range) |
| Core Architecture | 8-bit RISC (Harvard) |
| Instruction Set | 35 single-word instructions, 14-bit instruction word |
| Max CPU Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz / 1 us at 4 MHz |
| Program Memory (Flash) | 1.75 KB (1K x 14) |
| Data RAM | 68 bytes |
| Data EEPROM | 64 bytes |
| I/O Pins | 13 |
| Timers | 3 (TMR0, TMR1, TMR2 - WDT included) |
| ADC | None |
| Supply Voltage (VDD) | 4.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial, I grade) |
| Package | 18-pin SOIC (SO, .300") |
| Mounting Type | Surface Mount |
| Programming Method | ICSP (In-Circuit Serial Programming) |
| MSL Level | 1 (unlimited floor life) |
| RoHS Status | Compliant |
PIC16F84-04I/SO Pin Configuration
| Pin 1 | RA2 — Digital I/O pin / PORTA bit 2 |
| Pin 2 | RA3 — Digital I/O pin / PORTA bit 3 |
| Pin 3 | RA4/T0CKI — Digital I/O pin / TMR0 external clock input (open-drain) |
| Pin 4 | MCLR — Master Clear (active-low reset, pull-up required) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Digital I/O / External interrupt input |
| Pin 7 | RB1 — Digital I/O / PORTB bit 1 |
| Pin 8 | RB2 — Digital I/O / PORTB bit 2 |
| Pin 9 | RB3 — Digital I/O / PORTB bit 3 |
| Pin 10 | RB4 — Digital I/O / PORTB bit 4 (interrupt-on-change) |
| Pin 11 | RB5 — Digital I/O / PORTB bit 5 (interrupt-on-change) |
| Pin 12 | RB6/PGC — Digital I/O / ICSP clock (interrupt-on-change) |
| Pin 13 | RB7/PGD — Digital I/O / ICSP data (interrupt-on-change) |
| Pin 14 | VDD — Positive supply (4.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / Fosc/4 clock output |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — Digital I/O / PORTA bit 0 |
| Pin 18 | RA1 — Digital I/O / PORTA bit 1 |
Typical Applications
PIC16F84-04I/SO is suitable for 6 applications: Hobby and Educational Embedded Projects, Legacy Industrial Control Panels, Appliance and White-Goods Controllers, Automotive Body Electronics (Legacy Modules), Remote Controls and IR/RF Receivers, Smart Sensor Signal Conditioning.
Hobby and Educational Embedded Projects
The PIC16F84-04I/SO is a long-standing workhorse for hobbyist and educational embedded designs because of its simple 35-instruction mid-range core and forgiving ICSP programming model. The 4 MHz CPU clock delivers 1 microsecond instruction cycles, comfortably handling bit-banged serial protocols, simple state machines, and LED multiplexing without DMA or complex interrupts. The 1.75 KB Flash (1K x 14) is sufficient for small task schedulers and beginner tutorials, while the 13 I/O pins drive 7-segment displays and keypads directly. The 18-SOIC package is breadboard-friendly with a SOIC-to-DIP adapter. Per the Microchip PIC16F84 datasheet, the part's industrial -40C to +85C range lets students run the same code on lab benches, in garages, and outdoors.
Recommended
Legacy Industrial Control Panels
The PIC16F84-04I/SO suits legacy industrial control panels where deterministic response and long-term firmware stability matter more than feature density. Its 4 MHz clock gives 1 microsecond per instruction, enabling precise timing of mechanical relays and solenoids without RTOS overhead. The 13 I/O lines can directly drive transistor arrays for contactor coils while reading limit switches and selector dials, and the on-chip watchdog timer (WDT), power-on reset (POR), and brown-out reset (BOR) protect unattended panels against lockups. The industrial temperature grade (-40C to +85C) handles factory-floor heat. Per the Microchip datasheet, the 4.0-5.5V VDD range tolerates the rectified-but-unregulated rails common in industrial power supplies. This is exactly the use case Microchip's legacy-replacement program targets with the 16F84A.
Recommended
Appliance and White-Goods Controllers
In cost-sensitive appliance controllers like washing-machine front panels, dishwasher timers, microwave keypads, and refrigerator displays, the PIC16F84-04I/SO offers enough headroom for user-interface scanning and motor-driver handshakes. The 13 I/O lines multiplex 4x4 keypads plus 7-segment or character LCDs, while the integrated watchdog and brown-out reset prevent lockup during brown-outs from compressor inrush. The 1.75 KB Flash accommodates menu-handling and timing routines. Per Microchip datasheet DS30421D, the part's wide industrial temperature rating survives oven-cabinet or basement-mechanical-room environments. The 18-SOIC package is easy to wave-solder during high-throughput appliance manufacturing.
Recommended
Automotive Body Electronics (Legacy Modules)
The PIC16F84-04I/SO has historically been used in non-safety automotive body modules like window-lift controllers, mirror-adjust switches, interior-light timers, and remote-keyless-entry receivers. The industrial temperature rating (-40C to +85C) handles cabin environments though not under-hood. The 4 MHz clock and deterministic 1 microsecond instruction cycle suit bit-banged Manchester or PWM decoding for short-range remotes, and the integrated watchdog prevents lockup under noisy alternator conditions. Per the Microchip PIC16F84 datasheet, the part is rated for automotive OEM designs where AEC-Q100 is not mandated. For new designs, Microchip's automotive-grade PIC16F series is recommended.
Recommended
Remote Controls and IR/RF Receivers
Low-cost IR remote controls and RF receiver/decoders benefit from the PIC16F84-04I/SO's small footprint, deterministic interrupt response, and low-power sleep modes. The PIC16F84's INT pin on RB0 directly captures the demodulated IR carrier at 38 kHz, while TMR0 counts edges for protocol decoding. The 13 I/O lines drive status LEDs, pushbutton inputs, and zero-cross detection. Per the Microchip datasheet, the watchdog and brown-out reset prevent lockups when battery voltage dips. The 1.75 KB Flash holds universal remote code libraries. The 18-SOIC package fits inside slim remote-control enclosures. Battery life is dominated by the IR LED current, not the MCU.
Recommended
Smart Sensor Signal Conditioning
In low-end smart-sensor signal-conditioning applications like thermostat front ends, weather-station transmitters, and occupancy sensors, the PIC16F84-04I/SO handles I/O multiplexing, switch debouncing, and timing without ADC overhead. With a 4 MHz CPU clock and 1 microsecond instruction cycle, the MCU scans 4 sensor channels through analog muxes and discrete comparators, generating PWM or pulse-frequency outputs. The 13 I/O lines drive LEDs, relay coils, and buzzer outputs. The industrial temperature rating suits outdoor enclosures, and the 1.75 KB Flash holds calibration tables and protocol stacks. Per the Microchip datasheet, the integrated watchdog timer prevents stuck outputs in unattended sensor installations.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F84-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F84A-04I/SO | PIC16F84A-04I/P | PIC16F84-04I/P | PIC16F84-04/SO | PIC16F628A-04I/SO | PIC16F88-I/SO |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (SO, .300") | 18-SOIC (SO, .300") - same | 18-PDIP (P) - same family | 18-PDIP (P) - same family | 18-SOIC (SO, .300") - same | 18-SOIC (SO, .300") - same | 18-SOIC (SO, .300") - same |
| Max CPU Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz |
| Program Memory (Flash) | 1.75 KB (1K x 14) | 1.75 KB (1K x 14) | 1.75 KB (1K x 14) | 1.75 KB (1K x 14) | 1.75 KB (1K x 14) | 3.5 KB (2K x 14) | 7 KB (4K x 14) |
| Data RAM | 68 B | 68 B | 68 B | 68 B | 68 B | 224 B | 368 B |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 16 | 16 |
| Operating Voltage (VDD) | 4.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Internal Oscillator | No (external only) | Yes (4 MHz) | Yes (4 MHz) | No | No | Yes (4 MHz) | Yes (8 MHz) |
| ADC | None | None | None | None | None | None | 10-bit, 7 channels |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
Key Differentiators
- Industrial temperature grade in SOIC-18 package (vs PIC16F84-04/SO)
- Modern drop-in replacement with wider voltage and internal oscillator (vs PIC16F84A-04I/SO)
- More memory and peripherals in same SOIC-18 footprint (vs PIC16F628A-04I/SO)
- Through-hole alternative without re-layout (vs PIC16F84-04I/P)
Design Notes
Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the package, plus a 10 uF bulk capacitor on the PCB power rail. Per Microchip PIC16F84 datasheet DS30421D, VDD must remain inside 4.0 V to 5.5 V at all times - operation below 4.0 V may trigger the brown-out reset (BOR) depending on the BOR configuration bit. Add a TVS diode on VDD for industrial environments subject to load-dump transients.
Route the MCLR pin (pin 4) with a 10 kohm pull-up to VDD; do not leave it floating. Place the external crystal or resonator (if used) within 5 mm of pins 15 (OSC2/CLKOUT) and 16 (OSC1/CLKIN) with grounded guard traces to minimize stray capacitance. Per Microchip application note AN588, the ICSP pins RB6/PGC (pin 12) and RB7/PGD (pin 13) should be brought out to test points for production programming. Avoid routing high-speed signals across the OSC traces to prevent coupling.
Watch out for three common PIC16F84 design errors: (1) leaving RA4 open - it is an open-drain output and needs a pull-up when used as a digital output; (2) forgetting to clear the GIE bit during critical timing loops, which allows interrupts to corrupt cycle counts; (3) bank-switching errors when accessing registers in bank 1 without setting the RP0 bit in the STATUS register. Estimated: at 4 MHz Fosc, an interrupt latency of 4 instruction cycles (~4 microseconds) must be budgeted in worst-case response-time calculations.
The PIC16F84-04I/SO does not have dedicated hardware PWM or USART; bit-banged serial protocols must run at rates the 4 MHz instruction cycle can sustain without jitter. For 9600 baud UART emulation, the bit-time resolution is about 104 instruction cycles per bit, giving roughly +/-1% jitter with careful timing. Per the Microchip mid-range reference manual, using TMR1 as a time base improves accuracy. Critical applications should consider the PIC16F628A or PIC16F88 upgrades with on-datasleep USART hardware.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - for automotive designs requiring AEC-Q100, use Microchip's automotive-grade PIC16F variants.
